Fair Value Measurements - Long Term Debt (Details) - USD ($) $ in Millions	Jan. 31, 2020	Feb. 01, 2019
Financial Instruments
Long-term debt carrying value (excluding capitalized lease obligations)	$ 16,653	$ 14,727
Unsecured notes
Financial Instruments
Long-term debt carrying value (excluding capitalized lease obligations)	16,648	14,721
Mortgage notes
Financial Instruments
Long-term debt carrying value (excluding capitalized lease obligations)	5	6
Estimate of Fair Value
Financial Instruments
Long-term debt fair value (excluding capitalized lease obligations)	18,814	14,479
Estimate of Fair Value | Unsecured notes | Level 1
Financial Instruments
Long-term debt fair value (excluding capitalized lease obligations)	18,808	14,473
Estimate of Fair Value | Mortgage notes | Level 2
Financial Instruments
Long-term debt fair value (excluding capitalized lease obligations)	$ 6	$ 6